1. Field of the Invention
This invention relates to industrial sheet metal processing of work pieces and more particularly to an improvement in a linear punch press.
2. Description of the Prior Art
Sheet metal punch presses having a bridge type frame supporting a punching head have been used for some time.
However, such punching machines have usually been equipped with turret-type punching heads or cartridge-type punch and die sets moved into position with respect to a punching head or a ram. Both the turret-type and the cartridge-type die holding systems are subject to numerous disadvantages: such as the use of an alignment pin to align a punch and die; and, the use of gears, pulleys, chains and clutches, all having many wear points resulting in a misalignment of punches and dies as well as damaging a workpiece or structural components of the punch press.
U.S. Pat. No. 3,449,991, issued Jun. 17, 1969, to Daniels is an example of a punch press utilizing turrets for guiding the tooling into position for punching by a ram means.
U.S. Pat. No. 4,503,741, issued Mar. 12, 1985, to Hunter is an example of a bridge-type punching frame that features elongated sectionalized cartridges which carry the tooling and die cartridges and are moved together in a linear fashion.